Answer
False.
Work Step by Step
Take $k=1$, a positive $k$ value. $$10^{-k}=10^{-1}=\frac{1}{10^1}=\frac{1}{10}$$ This value is positive. Therefore, this statement must be false.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.